LONDON, July 23 -- Instagram's direct messages stopped working on Wednesday for the second time in three days, a repeat failure that Meta declined to explain publicly even as tens of thousands of users reported their inboxes frozen.

The outage, which concentrated on DMs rather than the broader app, began in the early afternoon UTC and triggered a spike on Downdetector, the independent platform that tracks service disruptions by aggregating user complaints. Reports clustered in North America, Europe, and parts of South Asia before the volume peaked and began to subside. Users who attempted to send messages encountered delivery failures, with some messages shown as unsent or stuck in an intermediate state.

It was the second such disruptio...